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Author Komendová, L.; Milošević, M.V.; Shanenko, A.A.; Peeters, F.M. url  doi
openurl 
  Title Different length scales for order parameters in two-gap superconductors : extended Ginzburg-Landau theory Type A1 Journal article
  Year 2011 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B  
  Volume 84 Issue 6 Pages 064522-064522,5  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Using the Ginzburg-Landau theory extended to the next-to-leading order, we determine numerically the healing lengths of the two order parameters at the two-gap superconductor/normal metal interface. We demonstrate on several examples that those can be different even in the strict domain of applicability of the Ginzburg-Landau theory. This justifies the use of this theory to describe relevant physics of two-gap superconductors, distinguishing them from their single-gap counterparts. The calculational degree of complexity increases only slightly with respect to the conventional Ginzburg-Landau expansion, thus the extended Ginzburg-Landau model remains numerically far less demanding compared to the full microscopic approaches.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos (down) 000294226000013 Publication Date 2011-08-25  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.836 Times cited 56 Open Access  
  Notes ; This work was supported by the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP), and the ESF-INSTANS network. ; Approved Most recent IF: 3.836; 2011 IF: 3.691  
  Call Number UA @ lucian @ c:irua:92414 Serial 695  
Permanent link to this record
 

 
Author Nourbakhsh, A.; Cantoro, M.; Klekachev, A.V.; Pourtois, G.; Vosch, T.; Hofkens, J.; van der Veen, M.H.; Heyns, M.M.; de Gendt, S.; Sels, B.F. doi  openurl
  Title Single layer vs bilayer graphene : a comparative study of the effects of oxygen plasma treatment on their electronic and optical properties Type A1 Journal article
  Year 2011 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C  
  Volume 115 Issue 33 Pages 16619-16624  
  Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract This contribution presents the effects of a mild O2 plasma treatment on the structural, optical, and electrical properties of single-layer (SLG) and bilayer graphene (BLG). Unexpectedly, we observe only photoluminescence in the SLG parts of a graphene flake composed of regions of various thickness upon O2 plasma treatment, whereas the BLG and few-layer graphene (FLG) parts remain optically unchanged. Confirmed with X-ray photoelectron spectroscopy (XPS) that O2 plasma induces epoxide and hydroxyl-like groups in graphene, density functional theory (DFT) calculations are carried out on representative epoxidized and hydroxylated SLG and BLG models to predict density of states (DOS) and band structures. Sufficiently oxidized SLG shows a bandgap and thus loss of semimetallic behavior, while oxidized BLG maintains its semimetallic behavior even at high oxygen density in agreement with the results of the photoluminescence spectroscopy (PL) experiments. DFT calculations confirm that the Fermi velocity in epoxidized BLG is remarkably comparable with that of pristine SLG, pointing to a similarity of electronic band structure. The similarity is also experimentally demonstrated by the electrical characterization of a plasma-treated BLG-FET. As expected from the electronegative oxygen adatoms in the graphene, epoxidized BLG presents conductive features typical of hole doping. Moreover, the electrical characteristics suggest band structures closely related to that of epoxidized graphene while deviating from that of hydroxylated graphene. Finally, upon O2 plasma treatment of BLG, the four-component 2D peak around 2700 cm1 in the Raman spectrum evolves into a single Lorentzian line, very like the 2D peak of pristine SLG. Summarizing, the data in this contribution recommend that a controlled O2 plasma treatment, which is compatible with CMOS process flow in contrast to wet chemical oxidation methods, provides an efficient and valuable technique to exploit the transport properties of the bottom layer of BLG.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos (down) 000294077000047 Publication Date 2011-06-24  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1932-7447;1932-7455; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.536 Times cited 46 Open Access  
  Notes Approved Most recent IF: 4.536; 2011 IF: 4.805  
  Call Number UA @ lucian @ c:irua:91715 Serial 3024  
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Author Shestakov, M.V.; Tikhomirov, V.K.; Kirilenko, D.; Kuznetsov, A.S.; Chibotaru, L.F.; Baranov, A.N.; Van Tendeloo, G.; Moshchalkov, V.V. url  doi
openurl 
  Title Quantum cutting in Li (770 nm) and Yb (1000 nm) co-dopant emission bands by energy transfer from the ZnO nano-crystalline host Type A1 Journal article
  Year 2011 Publication Optics express Abbreviated Journal Opt Express  
  Volume 19 Issue 17 Pages 15955-15964  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Li-Yb co-doped nano-crystalline ZnO has been synthesized by a method of thermal growth from the salt mixtures. X-ray diffraction, transmission electron microscopy, atomic absorption spectroscopy and optical spectroscopy confirm the doping and indicate that the dopants may form Li-Li and Yb3+-Li based nanoclusters. When pumped into the conduction and exciton absorption bands of ZnO between 250 to 425 nm, broad emission bands of about 100 nm half-height-width are excited around 770 and 1000 nm, due to Li and Yb dopants, respectively. These emission bands are activated by energy transfer from the ZnO host mostly by quantum cutting processes, which generate pairs of quanta in Li (770 nm) and Yb (1000 nm) emission bands, respectively, out of one quantum absorbed by the ZnO host. These quantum cutting phenomena have great potential for application in the down-conversion layers coupled to the Si solar cells.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos (down) 000293894900033 Publication Date 2011-08-04  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1094-4087; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.307 Times cited 19 Open Access  
  Notes FWO; Methusalem Approved Most recent IF: 3.307; 2011 IF: 3.587  
  Call Number UA @ lucian @ c:irua:92428 Serial 2776  
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Author Klimczuk, T.; Wang, C.H.; Lawrence, J.M.; Xu, Q.; Durakiewicz, T.; Ronning, F.; Llobet, A.; Trouw, F.; Kurita, N.; Tokiwa, Y.; Lee, H.o.; Booth, C.H.; Gardner, J.S.; Bauer, E.D.; Joyce, J.J.; Zandbergen, H.W.; Movshovich, R.; Cava, R.J.; Thompson, J.D.; url  doi
openurl 
  Title Crystal fields, disorder, and antiferromagnetic short-range order in Yb0.24Sn0.76Ru Type A1 Journal article
  Year 2011 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B  
  Volume 84 Issue 7 Pages 075152-075152,8  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract We report extensive measurements on a new compound (Yb0.24Sn0.76)Ru that crystallizes in the cubic CsCl structure. Valence-band photoemission (PES) and L3 x-ray absorption show no divalent component in the 4f configuration of Yb. Inelastic neutron scattering (INS) indicates that the eight-fold degenerate J-multiplet of Yb3+ is split by the crystalline electric field (CEF) into a Γ7-doublet ground state and a Γ8 quartet at an excitation energy 20 meV. The magnetic susceptibility can be fit very well by this CEF scheme under the assumption that a Γ6-excited state resides at 32 meV; however, the Γ8/Γ6 transition expected at 12 meV was not observed in the INS. The resistivity follows a Bloch-Grüneisen law shunted by a parallel resistor, as is typical of systems subject to phonon scattering with no apparent magnetic scattering. All of these properties can be understood as representing simple local moment behavior of the trivalent Yb ion. At 1 K there is a peak in specific heat that is too broad to represent a magnetic-phase transition, consistent with absence of magnetic reflections in neutron diffraction. On the other hand this peak also is too narrow to represent the Kondo effect in the Γ7-doublet ground state. On the basis of the field dependence of the specific heat, we argue that antiferromagnetic (AF) short-range order (SRO) (possibly coexisting with Kondo physics) occurs at low temperatures. The long-range magnetic order is suppressed because the Yb site occupancy is below the percolation threshold for this disordered compound.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos (down) 000293830800003 Publication Date 2011-08-15  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.836 Times cited 8 Open Access  
  Notes Esteem 026019 Approved Most recent IF: 3.836; 2011 IF: 3.691  
  Call Number UA @ lucian @ c:irua:92427 Serial 555  
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Author Liu, Y.; Cheng, F.; Li, X.J.; Peeters, F.M.; Chang, K. doi  openurl
  Title Tuning of anisotropy in two-electron quantum dots by spin-orbit interactions Type A1 Journal article
  Year 2011 Publication Applied physics letters Abbreviated Journal Appl Phys Lett  
  Volume 99 Issue 3 Pages 032102,1-032102,3  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract We investigate the influence of the spin-orbit interactions (SOIs) on the electron distribution and the optical absorption of a two-electron quantum dot. It is shown that the interplay between the SOIs makes the two-electron quantum dot behave like two laterally coupled quantum dots and the anisotropic distribution can be rotated from [110] to [11®0] by reversing the direction of the perpendicular electric field and detect it through the optical absorption spectrum.  
  Address  
  Corporate Author Thesis  
  Publisher American Institute of Physics Place of Publication New York, N.Y. Editor  
  Language Wos (down) 000293679000026 Publication Date 2011-07-18  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-6951; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.411 Times cited 8 Open Access  
  Notes ; This work was supported by NSFC Grants No. 16760525405, 10874175 and 11004017 and the Belgian Science Policy 168(IAP). ; Approved Most recent IF: 3.411; 2011 IF: 3.844  
  Call Number UA @ lucian @ c:irua:92473 Serial 3749  
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Author Bals, S.; Casavola, M.; van Huis, M.A.; Van Aert, S.; Batenburg, K.J.; Van Tendeloo, G.; Vanmaekelbergh, D. pdf  url
doi  openurl
  Title Three-dimensional atomic imaging of colloidal core-shell nanocrystals Type A1 Journal article
  Year 2011 Publication Nano letters Abbreviated Journal Nano Lett  
  Volume 11 Issue 8 Pages 3420-3424  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab  
  Abstract Colloidal coreshell semiconductor nanocrystals form an important class of optoelectronic materials, in which the exciton wave functions can be tailored by the atomic configuration of the core, the interfacial layers, and the shell. Here, we provide a trustful 3D characterization at the atomic scale of a free-standing PbSe(core)CdSe(shell) nanocrystal by combining electron microscopy and discrete tomography. Our results yield unique insights for understanding the process of cation exchange, which is widely employed in the synthesis of coreshell nanocrystals. The study that we present is generally applicable to the broad range of colloidal heteronanocrystals that currently emerge as a new class of materials with technological importance.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington Editor  
  Language Wos (down) 000293665600062 Publication Date 2011-07-25  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1530-6984;1530-6992; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 12.712 Times cited 121 Open Access  
  Notes Esteem 026019; Fwo Approved Most recent IF: 12.712; 2011 IF: 13.198  
  Call Number UA @ lucian @ c:irua:91263 Serial 3643  
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Author Quintana, M.; Montellano, A.; Esau del Rio Castillo, A.; Van Tendeloo, G.; Bittencourt, C.; Prato, M. pdf  doi
openurl 
  Title Selective organic functionalization of graphene bulk or graphene edges Type A1 Journal article
  Year 2011 Publication Chemical communications Abbreviated Journal Chem Commun  
  Volume 47 Issue 33 Pages 9330-9332  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Graphene sheets have been functionalized with a PAMAM dendron, finding that graphene can be efficiently functionalized all over the surface, or only at the edges, depending on the reactions used in the functionalization process.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication London Editor  
  Language Wos (down) 000293648200010 Publication Date 2011-07-20  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1359-7345;1364-548X; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 6.319 Times cited 84 Open Access  
  Notes Approved Most recent IF: 6.319; 2011 IF: 6.169  
  Call Number UA @ lucian @ c:irua:91892 Serial 2968  
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Author King, G.; Abakumov, A.M.; Woodward, P.M.; Llobet, A.; Tsirlin, A.A.; Batuk, D.; Antipov, E.V. doi  openurl
  Title The high-temperature polymorphs of K3AlF6 Type A1 Journal article
  Year 2011 Publication Inorganic chemistry Abbreviated Journal Inorg Chem  
  Volume 50 Issue 16 Pages 7792-7801  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract The crystal structures of the three high-temperature polymorphs of K3AlF6 have been solved from neutron powder diffraction, synchrotron X-ray powder diffraction, and electron diffraction data. The β-phase (stable between 132 and 153 °C) and γ-phase (stable between 153 to 306 °C) can be described as unusually complex superstructures of the double-perovskite structure (K2KAlF6) which result from noncooperative tilting of the AlF6 octahedra. The β-phase is tetragonal, space group I4/m, with lattice parameters of a = 13.3862(5) Å and c = 8.5617(3) Å (at 143 °C) and Z = 10. In this phase, one-fifth of the AlF6 octahedra are rotated about the c-axis by 45° while the other four-fifths remain untilted. The large 45° rotations result in edge sharing between these AlF6 octahedra and the neighboring K-centered polyhedra, resulting in pentagonal bipyramidal coordination for four-fifths of the K+ ions that reside on the B-sites of the perovskite structure. The remaining one-fifth of the K+ ions on the B-sites retain octahedral coordination. The γ-phase is orthorhombic, space group Fddd, with lattice parameters of a = 36.1276(4) Å, b = 17.1133(2) Å, and c = 12.0562(1) Å (at 225 °C) and Z = 48. In the γ-phase, one-sixth of the AlF6 octahedra are randomly rotated about one of two directions by 45° while the other five-sixths remain essentially untilted. These rotations result in two-thirds of the K+ ions on the B-site obtaining 7-fold coordination while the other one-third remain in octahedral coordination. The δ-phase adopts the ideal cubic double-perovskite structure, space group Fmm, with a = 8.5943(1) Å at 400 °C. However, pair distribution function analysis shows that locally the δ-phase is quite different from its long-range average crystal structure. The AlF6 octahedra undergo large-amplitude rotations which are accompanied by off-center displacements of the K+ ions that occupy the 12-coordinate A-sites.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Easton, Pa Editor  
  Language Wos (down) 000293493100052 Publication Date 2011-07-11  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0020-1669;1520-510X; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.857 Times cited 19 Open Access  
  Notes Approved Most recent IF: 4.857; 2011 IF: 4.601  
  Call Number UA @ lucian @ c:irua:91131 Serial 1468  
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Author de Clippel, F.; Harkiolakis, A.; Vosch, T.; Ke, X.; Giebeler, L.; Oswald, S.; Houthoofd, K.; Jammaer, J.; Van Tendeloo, G.; Martens, J.A.; Jacobs, P.A.; Baron, G.V.; Sels, B.F.; Denayer, J.F.M. pdf  doi
openurl 
  Title Graphitic nanocrystals inside the pores of mesoporous silica : synthesis, characterization and an adsorption study Type A1 Journal article
  Year 2011 Publication Microporous and mesoporous materials: zeolites, clays, carbons and related materials Abbreviated Journal Micropor Mesopor Mat  
  Volume 144 Issue 1/3 Pages 120-133  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract This work presents a new carbonsilica hybrid material, denoted as CSM, with remarkable sorption properties. It consists of intraporous graphitic nanocrystals grown in the pores of mesoporous silica. CSM is obtained by a subtle incipient wetness impregnation of Al-containing mesoporous silica with furfuryl alcohol (FA)/hemelitol solutions. Both the volume match of the impregnation solution with that of the silica template pore volume, and the presence of Al3+ in the silica, are crucial to polymerize FA selectively inside the mesopores. Carbonization of the intraporous polymer was then performed by pyrolysis under He up to 1273 K. The resulting CSMs were examined by SEM, HRTEM, 27Al MAS NMR, N2 adsorption, XRD, TGA, TPD, XPS, pycnometry and Raman spectroscopy. Mildly oxidized graphitic-like carbon nanoblocks, consisting of a few graphene-like sheets, were thus identified inside the template mesopores. Random stacking of these carbon crystallites generates microporosity resulting in biporous materials at low carbon content and microporous materials at high carbon loadings. Very narrow pore distributions were obtained when pyrolysis was carried out under slow heating rate, viz. 1 K min−1. Adsorption and shape selective properties of the carbon filled mesoporous silica were studied by performing pulse chromatography and breakthrough experiments, and by measuring adsorption isotherms of linear and branched alkanes. Whereas the parent mesoporous silica shows unselective adsorption, their CSM analogues preferentially adsorb linear alkanes. The sorption capacity and selectivity can be adjusted by changing the pore size of the template or by varying the synthesis conditions. A relation between the carbon crystallites size and the shape selective behaviour of the corresponding CSM for instance is demonstrated. Most interestingly, CSM shows separation factors for linear and branched alkanes up to values comparable to those of zeolitic molecular sieves.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos (down) 000293435400016 Publication Date 2011-04-15  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1387-1811; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.615 Times cited 15 Open Access  
  Notes Approved Most recent IF: 3.615; 2011 IF: 3.285  
  Call Number UA @ lucian @ c:irua:92325 Serial 1380  
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Author Hadermann, J.; Abakumov, A.M.; Turner, S.; Hafideddine, Z.; Khasanova, N.R.; Antipov, E.V.; Van Tendeloo, G. pdf  doi
openurl 
  Title Solving the structure of Li ion battery materials with precession electron diffraction : application to Li2CoPo4F Type A1 Journal article
  Year 2011 Publication Chemistry of materials Abbreviated Journal Chem Mater  
  Volume 23 Issue 15 Pages 3540-3545  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract The crystal structure of the Li2CoPO4F high-voltage cathode for Li ion rechargeable batteries has been completely solved from precession electron diffraction (PED) data, including the location of the Li atoms. The crystal structure consists of infinite chains of CoO4F2 octahedra sharing common edges and linked into a 3D framework by PO4 tetrahedra. The chains and phosphate anions together delimit tunnels filled with the Li atoms. This investigation demonstrates that PED can be successfully applied for obtaining structural information on a variety of Li-containing electrode materials even from single micrometer-sized crystallites.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos (down) 000293357100019 Publication Date 2011-07-11  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0897-4756;1520-5002; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 9.466 Times cited 46 Open Access  
  Notes Fwo; Bof Approved Most recent IF: 9.466; 2011 IF: 7.286  
  Call Number UA @ lucian @ c:irua:90357 Serial 3053  
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Author Xu, B.; Milošević, M.V.; Lin, S.-H.; Peeters, F.M.; Jankó, B. url  doi
openurl 
  Title Formation of multiple-flux-quantum vortices in mesoscopic superconductors from simulations of calorimetric, magnetic, and transport properties Type A1 Journal article
  Year 2011 Publication Physical review letters Abbreviated Journal Phys Rev Lett  
  Volume 107 Issue 5 Pages 057002,1-057002,4  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Because of strong flux confinement in mesoscopic superconductors, a giant vortex may appear in the ground state of the system in an applied magnetic field. This multiquanta vortex can then split into individual vortices (and vice versa) as a function of, e.g., applied current, magnetic field, or temperature. Here we show that such transitions can be identified by calorimetry, as the formation or splitting of a giant vortex results in a clear jump in measured heat capacity versus external drive. We attribute this phenomenon to an abrupt change in the density of states of the quasiparticle excitations in the vortex core(s), and further link it to a sharp change of the magnetic susceptibility at the transitionproving that the formation of a giant vortex can also be detected by magnetometry.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication New York, N.Y. Editor  
  Language Wos (down) 000293333100006 Publication Date 2011-07-29  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0031-9007;1079-7114; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 8.462 Times cited 26 Open Access  
  Notes ; We thank O. Bourgeois, T. Yokoyama, M. Eschrig, and M. Ichioka for discussions. This work was supported by FWO-Vlaanderen, the Belgian Science Policy (IAP), the bilateral project Flanders-USA, NSF NIRT, ECS-0609249, and Institute of Theoretical Sciences, Notre Dame. ; Approved Most recent IF: 8.462; 2011 IF: 7.370  
  Call Number UA @ lucian @ c:irua:91237 Serial 1263  
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Author Zarenia, M.; Pereira, J.M.; Peeters, F.M.; Farias, G. de A. url  doi
openurl 
  Title Topological confinement in an antisymmetric potential in bilayer graphene in the presence of a magnetic field Type A1 Journal article
  Year 2011 Publication Nanoscale research letters Abbreviated Journal Nanoscale Res Lett  
  Volume 6 Issue Pages 452,1-452,10  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract We investigate the effect of an external magnetic field on the carrier states that are localized at a potential kink and a kink-antikink in bilayer graphene. These chiral states are localized at the interface between two potential regions with opposite signs.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication New York, N.Y. Editor  
  Language Wos (down) 000293299800001 Publication Date 2011-07-14  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1556-276X; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.833 Times cited 4 Open Access  
  Notes ; This work was supported by the Brazilian agency CNPq (Pronex), the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP), and the bilateral projects between Flanders and Brazil and FWO-CNPq. ; Approved Most recent IF: 2.833; 2011 IF: NA  
  Call Number UA @ lucian @ c:irua:91745 Serial 3674  
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Author Tsirlin, A.A.; Nath, R.; Abakumov, A.M.; Furukawa, Y.; Johnston, D.C.; Hemmida, M.; Krug von Nidda, H.-A.; Loidl, A.; Geibel, C.; Rosner, H. url  doi
openurl 
  Title Phase separation and frustrated square lattice magnetism of Na1.5VOPO4F0.5 Type A1 Journal article
  Year 2011 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B  
  Volume 84 Issue 1 Pages 014429-014429,16  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Crystal structure, electronic structure, and magnetic behavior of the spin-1/2 quantum magnet Na1.5VOPO4F0.5 are reported. The disorder of Na atoms leads to a sequence of structural phase transitions revealed by synchrotron x-ray powder diffraction and electron diffraction. The high-temperature second-order α↔β transition at 500 K is of the order-disorder type, whereas the low-temperature β↔γ+γ′ transition around 250 K is of the first order and leads to a phase separation toward the polymorphs with long-range (γ) and short-range (γ′) order of Na. Despite the complex structural changes, the magnetic behavior of Na1.5VOPO4F0.5 probed by magnetic susceptibility, heat capacity, and electron spin resonance measurements is well described by the regular frustrated square lattice model of the high-temperature α-polymorph. The averaged nearest-neighbor and next-nearest-neighbor couplings are J̅ 1≃−3.7 K and J̅ 2≃6.6 K, respectively. Nuclear magnetic resonance further reveals the long-range ordering at TN=2.6 K in low magnetic fields. Although the experimental data are consistent with the simplified square-lattice description, band structure calculations suggest that the ordering of Na atoms introduces a large number of inequivalent exchange couplings that split the square lattice into plaquettes. Additionally, the direct connection between the vanadium polyhedra induces an unusually strong interlayer coupling having effect on the transition entropy and the transition anomaly in the specific heat. Peculiar features of the low-temperature crystal structure and the relation to isostructural materials suggest Na1.5VOPO4F0.5 as a parent compound for the experimental study of tetramerized square lattices as well as frustrated square lattices with different values of spin.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos (down) 000293247400008 Publication Date 2011-07-28  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.836 Times cited 47 Open Access  
  Notes Approved Most recent IF: 3.836; 2011 IF: 3.691  
  Call Number UA @ lucian @ c:irua:91770 Serial 2588  
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Author Orlinskii, S.B.; Bogomolov, R.S.; Kiyamova, A.M.; Yavkin, B.V.; Mamin, G.M.; Turner, S.; Van Tendeloo, G.; Shiryaev, A.A.; Vlasov, I.I.; Shenderova, O. pdf  doi
openurl 
  Title Identification of substitutional nitrogen and surface paramagnetic centers in nanodiamond of dynamic synthesis by electron paramagnetic resonance Type A1 Journal article
  Year 2011 Publication Nanoscience and nanotechnology letters Abbreviated Journal Nanosci Nanotech Let  
  Volume 3 Issue 1 Pages 63-67  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Production of nanodiamond particles containing substitutional nitrogen is important for a wide variety of advanced applications. In the current work nanodiamond particles synthesized from a mixture of graphite and hexogen were analyzed to determine the presence of substitutional nitrogen using pulsed electron paramagnetic resonance (EPR) spectroscopy. Nitrogen paramagnetic centers in the amount of 1.2 ppm have been identified. The spin relaxation characteristics for both nitrogen and surface defects are also reported. A new approach for efficient depletion of the strong non-nitrogen EPR signal in nanodiamond material by immersing nanodiamond particles into ice matrix is suggested. This approach allows an essential decrease of the spin relaxation time of the dominant non-nitrogen defects, while preserving the substitutional nitrogen spin relaxation time.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos (down) 000293211200012 Publication Date 2011-09-19  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1941-4900;1941-4919; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 1.889 Times cited 14 Open Access  
  Notes Approved Most recent IF: 1.889; 2011 IF: 0.528  
  Call Number UA @ lucian @ c:irua:91943 Serial 1548  
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Author Grodzinska, D.; Pietra, F.; van Huis, M.A.; Vanmaekelbergh, D.; de Mello Donegá, C. url  doi
openurl 
  Title Thermally induced atomic reconstruction of PbSe/CdSe core/shell quantum dots into PbSe/CdSe bi-hemisphere hetero-nanocrystals Type A1 Journal article
  Year 2011 Publication Journal of materials chemistry Abbreviated Journal J Mater Chem  
  Volume 21 Issue 31 Pages 11556-11565  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract The properties of hetero-nanocrystals (HNCs) depend strongly on the mutual arrangement of the nanoscale components. In this work we have investigated the structural and morphological evolution of colloidal PbSe/CdSe core/shell quantum dots upon annealing under vacuum. Prior to annealing the PbSe core has an approximately octahedral morphology with eight {111} facets, and the CdSe shell has zinc-blende crystal structure. Thermal annealing under vacuum at temperatures between 150 °C and 200 °C induces a structural and morphological reconstruction of the HNCs whereby the PbSe core and the CdSe shell are reorganized into two hemispheres joined by a common {111} Se plane. This thermally induced reconstruction leads to considerable changes in the optical properties of the colloidal PbSe/CdSe HNCs.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Cambridge Editor  
  Language Wos (down) 000293190200018 Publication Date 2011-04-21  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0959-9428;1364-5501; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited 44 Open Access  
  Notes Approved Most recent IF: NA  
  Call Number UA @ lucian @ c:irua:91945 Serial 3632  
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Author Glazov, M.M.; Semina, M.A.; Badalyan, S.M.; Vignale, G. url  doi
openurl 
  Title Spin-current generation from Coulomb-Rashba interaction in semiconductor bilayers Type A1 Journal article
  Year 2011 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B  
  Volume 84 Issue 3 Pages 033305-033305,4  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Electrons in double-layer semiconductor heterostructures experience a special type of spin-orbit interaction that arises in each layer from the perpendicular component of the Coulomb electric field created by electron-density fluctuations in the other layer. We show that this interaction, acting in combination with the usual spin-orbit interaction, can generate a spin current in one layer when a charge current is driven in the other. This effect is distinct symmetrywise from the spin-Hall drag. The spin current is not, in general, perpendicular to the drive current.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos (down) 000293129200001 Publication Date 2011-07-26  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.836 Times cited 5 Open Access  
  Notes ; M.M.G. and M. A. S. are grateful to RFBR, EU projects Spinoptronics and POLAPHEN, and the “Dynasty” Foundation-ICFPM for financial support. S. M. B. acknowledges support from EU Grant No. PIIF-GA-2009-235394, the DFG SFB 689, and the Belgium Science Policy (IAP). G. V. acknowledges support from NSF Grant No. DMR-0705460. ; Approved Most recent IF: 3.836; 2011 IF: 3.691  
  Call Number UA @ lucian @ c:irua:91740 Serial 3081  
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Author Tognalii, N.G.; Cortés, E.; Hernández-Nieves, A.D.; Carro, P.; Usaj, G.; Balseiro, C.A.; Vela, M.E.; Salvarezza, R.C.; Fainstein, A. doi  openurl
  Title From single to multiple Ag-layer modification of Au nanocavity substrates : a tunable probe of the chemical surface-enhanced Raman scattering mechanism Type A1 Journal article
  Year 2011 Publication ACS nano Abbreviated Journal Acs Nano  
  Volume 5 Issue 7 Pages 5433-5443  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract We present experimental and computational results that enlighten the mechanisms underlying the chemical contribution to surface-enhanced Raman scattering (SERS). Gold void metallic arrays electrochemically covered either by a Ag monolayer or 10100 Ag layers were modified with a self-assembled monolayer of 4-mercaptopyridine as a molecular Raman probe displaying a rich and unexpected Raman response. A resonant increase of the Raman intensity in the red part of the spectrum is observed that cannot be related to plasmon excitations of the cavity-array. Notably, we find an additional 1020 time increase of the SERS amplification upon deposition of a single Ag layer on the Au substrate, which is, however, almost quenched upon deposition of 10 atomic layers. Further deposition of 100 atomic Ag layers results in a new increase of the SERS signal, consistent with the improved plasmonic efficiency of Ag bulk-like structures. The SERS response as a function of the Ag layer thickness is analyzed in terms of ab initio calculations and a microscopic model for the SERS chemical mechanism based on a resonant charge transfer process between the molecular HOMO state and the Fermi level in the metal surface. We find that a rearrangement of the electronic charge density related to the presence of the Ag monolayer in the Au/Ag/molecule complex causes an increase in the distance between the HOMO center of charge and the metallic image plane that is responsible for the variation of Raman enhancement between the studied substrates. Our results provide a general platform for studying the chemical contribution to SERS, and for enhancing the Raman efficiency of tailored Au-SERS templates through electrochemical modification with Ag films.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos (down) 000293035200019 Publication Date 2011-06-15  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1936-0851;1936-086X; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 13.942 Times cited 26 Open Access  
  Notes ; We acknowledge financial support from ANPCyT (Argentina, PICT08-1617, PICT08-2236, PICT06-621, PICT-CNPQ-08-0019, PAE 22711, PICT06-01061, PICT06-483) and Project CTQ2008-06017/BQU, Spain. N.G.T, E.C., A.D.H.N., R.C.S, G.U., C.A.B., and A.F. are also at CONICET. M.E.V. is a member of the research career of CIC BsAs. R.C.S., C.A.B., and A.F. are Guggenheim Foundation Fellows. We would like to thank Dr. M. H. Fonticelli for fruitful discussions on the electrochemical measurements and Dr. H. Pastoriza for the help with the SEM measurements. ; Approved Most recent IF: 13.942; 2011 IF: 11.421  
  Call Number UA @ lucian @ c:irua:91775 Serial 1285  
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Author Masir, M.R.; Vasilopoulos, P.; Peeters, F.M. pdf  doi
openurl 
  Title Graphene in inhomogeneous magnetic fields : bound, quasi-bound and scattering states Type A1 Journal article
  Year 2011 Publication Journal of physics : condensed matter Abbreviated Journal J Phys-Condens Mat  
  Volume 23 Issue 31 Pages 315301,1-315301,14  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract The electron states in graphene-based magnetic dot and magnetic ring structures and combinations of both are investigated. The corresponding spectra are studied as a function of the radii, the strengths of the inhomogeneous magnetic field and of a uniform background field, the strength of an electrostatic barrier and the angular momentum quantum number. In the absence of an external magnetic field we have only long-lived quasi-bound and scattering states and we assess their influence on the density of states. In addition, we consider elastic electron scattering by a magnetic dot, whose average B vanishes, and show that the Hall and longitudinal resistivities, as a function of the Fermi energy, exhibit a pronounced oscillatory structure due to the presence of quasi-bound states. Depending on the dot parameters this oscillatory structure differs substantially for energies below and above the first Landau level.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication London Editor  
  Language Wos (down) 000293008900002 Publication Date 2011-07-16  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0953-8984;1361-648X; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.649 Times cited 38 Open Access  
  Notes ; This work was supported by the European Science Foundation (ESF) under the EUROCORES Program EuroGRAPHENE, the Canadian NSERC grant no. OGP0121756 and the Belgian Science Policy (IAP). We acknowledge discussions and correspondence with Professor A Matulis. ; Approved Most recent IF: 2.649; 2011 IF: 2.546  
  Call Number UA @ lucian @ c:irua:91176 Serial 1372  
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Author Vansweevelt, R.; Mortet, V.; D' Haen, J.; Ruttens, bart; van Haesendonck, C.; Partoens, B.; Peeters, F.M.; Wagner, P. doi  openurl
  Title Study on the giant positive magnetoresistance and Hall effect in ultrathin graphite flakes Type A1 Journal article
  Year 2011 Publication Physica status solidi : A : applications and materials science Abbreviated Journal Phys Status Solidi A  
  Volume 208 Issue 6 Pages 1252-1258  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract In this paper, we report on the electronic transport properties of mesoscopic, ultrathin graphite flakes with a thickness corresponding to a stack of 150 graphene layers. The graphite flakes show an unexpectedly strong positive magnetoresistance (PMR) already at room temperature, which scales in good approximation with the square of the magnetic field. Furthermore, we show that the resistivity is unaffected by magnetic fields oriented in plane with the graphene layers. Hall effect measurements indicate that the charge carriers are p-type and their concentration increases with increasing temperature while the mobility is decreasing. The Hall voltage is non-linear in higher magnetic fields. Possible origins of the observed effects are discussed. Ball and stick model of the two topmost carbon layers of the hexagonal graphite structure.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos (down) 000292945800008 Publication Date 2011-02-24  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1862-6300; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 1.775 Times cited 8 Open Access  
  Notes ; The authors gratefully acknowledge the support by FWO – Research Foundation Flanders (project G.0159.07 “Structural and electronic properties of biologically modified, graphene-based layers”), by the Federal Belgian Interuniversity Attraction Poles Programme BELSPO (project TAP VI P6/42 “Quantum effects in clusters and nanowires”) and by the Methusalem network “NANO – Antwerp-Hasselt,” funded by the Flemish Community. Technical assistance by Stoffel D. Janssens (magnet calibration and software development), Dr. Hong Yin (AFM-based thickness studies), Dr. Ronald Thoelen (data analysis), and Prof. Hans-Gerd Boyen (XPS spectroscopy) is greatly appreciated. ; Approved Most recent IF: 1.775; 2011 IF: 1.463  
  Call Number UA @ lucian @ c:irua:91941 Serial 3343  
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Author Kontozova-Deutsch, V.; Cardell, carolina; Urosevic, M.; Ruiz-Agudo, E.; Deutsch, F.; Van Grieken, R. doi  openurl
  Title Characterization of indoor and outdoor atmospheric pollutants impacting architectural monuments : the case of San Jerónimo Monastery (Granada, Spain) Type A1 Journal article
  Year 2011 Publication Environmental earth sciences Abbreviated Journal  
  Volume 63 Issue 7/8 Pages 1433-1445  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract Indoor and outdoor concentrations of atmospheric gaseous pollutants as well as composition, size, and morphology of particulate matter have been investigated at the monastery of San Jerónimo in Granada (Southern Spain). Complementary micro- and nano-analytical techniques were applied; elemental and mineralogical composition and morphological characteristics of particulate matter were investigated combining electron probe microanalysis at the single particle level, and bulk aerosol samples were analyzed using energy-dispersive X-ray fluorescence, X-ray diffraction, scanning electron microscopy with energy-dispersive X-ray analyzer and transmission electron microscopy (TEM). Microclimatic conditions at the monastery were monitored, and gas concentrations were assessed by means of diffusion tubes subsequently analyzed with ion chromatography. Results revealed high abundances of soil dust particles (aluminosilicates, calcite, dolomite, quartz), salt aerosols (chlorides, sulfates and ammonium-rich salts), and NO2 and SO2 both outdoors and indoors. Amorphous black carbon particles had surprisingly high abundances for Granada, a non-industrialized city. The composition of indoor particles corresponds to severe weathering affecting the construction materials and artworks inside the church; moreover their composition promotes a feedback process that intensifies the deterioration. Chemical reactions between chloride-rich salts and pigments from paintings were confirmed by TEM analyses. Indoors, blackening of surface decorative materials is fostered by particle re-suspension due to cleaning habits in the monastery (i.e. dusting). This is the first air quality study performed in a monument in the city of Granada with the aim of developing a strategy for preventive conservation.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos (down) 000292744300003 Publication Date 2010-07-19  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1866-6280 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited Open Access  
  Notes Approved no  
  Call Number UA @ admin @ c:irua:90766 Serial 7630  
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Author Dixon, E.; Hadermann, J.; Hayward, M.A. doi  openurl
  Title The synthesis and complex anion-vacancy ordered structure of La0.33Sr0.67MnO2.42 Type A1 Journal article
  Year 2011 Publication Journal of solid state chemistry Abbreviated Journal J Solid State Chem  
  Volume 184 Issue 7 Pages 1791-1799  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract The low-temperature topotactic reduction of La0.33Sr0.67MnO3 with NaH results in the formation of La0.33Sr0.67MnO2.42. A combination of neutron powder and electron diffraction data show that La0.33Sr0.67MnO2.42 adopts a novel anion-vacancy ordered structure with a 6-layer OOTOOT' stacking sequence of the octahedral and tetrahedral layers (Pcmb, a=5.5804(1) Å, b=23.4104(7) Å, c=11.2441(3) Å). A significant concentration of anion vacancies at the anion site, which links neighbouring octahedral layers means that only 25% of the octahedral manganese coordination sites actually have 6-fold MnO6 coordination, the remainder being MnO5 square-based pyramidal sites. The chains of cooperatively twisted apex-linked MnO4 tetrahedra adopt an ordered -LRLR- arrangement within each tetrahedral layer. This is the first published example of a fully refined structure of this type which exhibits such intralayer ordering of the twisted tetrahedral chains. The rationale behind the contrasting structures of La0.33Sr0.67MnO2.42 and other previously reported reduced La1−xSrxMnO3−y phases is discussed.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication London Editor  
  Language Wos (down) 000292718500032 Publication Date 2011-05-26  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0022-4596; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.299 Times cited 8 Open Access  
  Notes Approved Most recent IF: 2.299; 2011 IF: 2.159  
  Call Number UA @ lucian @ c:irua:90885 Serial 3600  
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Author Bogaerts, A.; Aghaei, M.; Autrique, D.; Lindner, H.; Chen, Z.; Wendelen, W. doi  isbn
openurl 
  Title Computer simulations of laser ablation, plume expansion and plasma formation Type H1 Book chapter
  Year 2011 Publication Abbreviated Journal  
  Volume Issue Pages 1-10  
  Keywords H1 Book chapter; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Trans Tech Place of Publication Aedermannsdorf Editor  
  Language Wos (down) 000292658900001 Publication Date 2011-04-20  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1662-8985; ISBN 978-3-03785-081-7 Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited 8 Open Access  
  Notes Approved Most recent IF: NA  
  Call Number UA @ lucian @ c:irua:88340 Serial 470  
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Author Jehanathan, N.; Georgieva, V.; Saraiva, M.; Depla, D.; Bogaerts, A.; Van Tendeloo, G. pdf  doi
openurl 
  Title The influence of Cr and Y on the micro structural evolution of Mg―Cr―O and Mg―Y―O thin films Type A1 Journal article
  Year 2011 Publication Thin solid films : an international journal on the science and technology of thin and thick films Abbreviated Journal Thin Solid Films  
  Volume 519 Issue 16 Pages 5388-5396  
  Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); Electron microscopy for materials research (EMAT)  
  Abstract The compositional influence of Cr and Y on the microstructure of Mg―Cr―O, and Mg―Y―O films synthesized by reactive magnetron sputtering has been investigated by transmission electron microscopy, X-ray diffraction and molecular dynamics simulations. A decrease in crystallinity is observed in these films as the M (Cr or Y) content is increased. It is found that M forms a solid solution with MgO for metal ratios up to ~ 70% and ~ 50% for Cr and Y respectively. Above ~ 70% Cr metal ratio the Mg―Cr―O films are found to be completely amorphous. The Mg―Y―O films are composed of Mg(Y)O and Y2O3 nano crystallites, up to ~ 50% Y metal ratio. Above this ratio, only Y2O3 nano crystallites are found. The preferential < 111> MgO grain alignment is strongly affected by the increase in M content. For M metal ratios up to ~ 50%, there is a selective promotion of the < 100> MgO grain alignments and a decline in the < 111> grain alignments.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Lausanne Editor  
  Language Wos (down) 000292573500013 Publication Date 2011-02-26  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0040-6090; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 1.879 Times cited 4 Open Access  
  Notes Iwt Approved Most recent IF: 1.879; 2011 IF: 1.890  
  Call Number UA @ lucian @ c:irua:89516 Serial 1618  
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Author Vandenberghe, W.; Sorée, B.; Magnus, W.; Fischetti, M.V. doi  openurl
  Title Generalized phonon-assisted Zener tunneling in indirect semiconductors with non-uniform electric fields : a rigorous approach Type A1 Journal article
  Year 2011 Publication Journal of applied physics Abbreviated Journal J Appl Phys  
  Volume 109 Issue 12 Pages 124503-124503,12  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract A general framework to calculate the Zener current in an indirect semiconductor with an externally applied potential is provided. Assuming a parabolic valence and conduction band dispersion, the semiconductor is in equilibrium in the presence of the external field as long as the electron-phonon interaction is absent. The linear response to the electron-phonon interaction results in a non-equilibrium system. The Zener tunneling current is calculated from the number of electrons making the transition from valence to conduction band per unit time. A convenient expression based on the single particle spectral functions is provided, enabling the evaluation of the Zener tunneling current under any three-dimensional potential profile. For a one-dimensional potential profile an analytical expression is obtained for the current in a bulk semiconductor, a semiconductor under uniform field, and a semiconductor under a non-uniform field using the WKB (Wentzel-Kramers-Brillouin) approximation. The obtained results agree with the Kane result in the low field limit. A numerical example for abrupt p-n diodes with different doping concentrations is given, from which it can be seen that the uniform field model is a better approximation than the WKB model, but a direct numerical treatment is required for low bias conditions.  
  Address  
  Corporate Author Thesis  
  Publisher American Institute of Physics Place of Publication New York, N.Y. Editor  
  Language Wos (down) 000292331200134 Publication Date 2011-06-21  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0021-8979; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.068 Times cited 41 Open Access  
  Notes ; William Vandenberghe gratefully acknowledges the support of a Ph.D. stipend from the Institute for the Promotion of Innovation through Science and Technology in Flanders (IWT-Vlaanderen). ; Approved Most recent IF: 2.068; 2011 IF: 2.168  
  Call Number UA @ lucian @ c:irua:90808 Serial 1325  
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Author Nowak, M.P.; Szafran, B.; Peeters, F.M.; Partoens, B.; Pasek, W.J. url  doi
openurl 
  Title Tuning of the spin-orbit interaction in a quantum dot by an in-plane magnetic field Type A1 Journal article
  Year 2011 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B  
  Volume 83 Issue 24 Pages 245324-245324,12  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Using an exact-diagonalization approach we show that one- and two-electron InAs quantum dots exhibit an avoided crossing in the energy spectra that is induced by the spin-orbit coupling in the presence of an in-plane external magnetic field. The width of the avoided crossings depends strongly on the orientation of the magnetic field, which reveals the intrinsic anisotropy of the spin-orbit-coupling interactions. We find that for specific orientations of the magnetic field avoided crossings vanish. A value of this orientation can be used to extract the ratio of the strength of Rashba and Dresselhaus interactions. The spin-orbit anisotropy effects for various geometries and orientations of the confinement potential are discussed. Our analysis explains the physics behind the recent measurements performed on a gated self-assembled quantum dot [ S. Takahashi et al. Phys. Rev. Lett. 104 246801 (2010)].  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos (down) 000292254000005 Publication Date 2011-06-30  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.836 Times cited 27 Open Access  
  Notes ; The authors thank S. Takahashi for helpful discussions. This work was supported by the “Krakow Interdisciplinary PhD Project in Nanoscience and Advanced Nanostructures” operated within the Foundation for Polish Science MPD Programme co-financed by the EU European Regional Development Fund, the Project No. N N202103938 supported by the Ministry of Science an Higher Education (MNiSW) for 2010-2013, and the Belgian Science Policy (IAP). W. J. P. has been partially supported by the EU Human Capital Operation Program, Polish Project No. POKL.04.0101-00-434/08-00. Calculations were performed in ACK-CYFRONET-AGH on the RackServer Zeus. ; Approved Most recent IF: 3.836; 2011 IF: 3.691  
  Call Number UA @ lucian @ c:irua:90923 Serial 3755  
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Author Neek-Amal, M.; Peeters, F.M. url  doi
openurl 
  Title Lattice thermal properties of graphane : thermal contraction, roughness, and heat capacity Type A1 Journal article
  Year 2011 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B  
  Volume 83 Issue 23 Pages 235437-235437,6  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Using atomistic simulations, we determine the roughness and the thermal properties of a suspended graphane sheet. As compared to graphene, we found that (i) hydrogenated graphene has a larger thermal contraction, (ii) the roughness exponent at room temperature is smaller, i.e., ≃ 1.0 versus ≃ 1.2 for graphene, (iii) the wavelengths of the induced ripples in graphane cover a wide range corresponding to length scales in the range 30125 Å at room temperature, and (iv) the heat capacity of graphane is estimated to be 29.32±0.23 J/mol K, which is 14.8% larger than that for graphene, i.e., 24.98±0.14 J/mol K. Above 1500 K, we found that graphane buckles when its edges are supported in the x-y plane.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos (down) 000292253400011 Publication Date 2011-06-30  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.836 Times cited 42 Open Access  
  Notes ; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Belgium Science Policy (IAP). ; Approved Most recent IF: 3.836; 2011 IF: 3.691  
  Call Number UA @ lucian @ c:irua:90921 Serial 1803  
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Author Chaves, A.; Komendová, L.; Milošević, M.V.; Andrade, J.S.; Farias, G.A.; Peeters, F.M. url  doi
openurl 
  Title Conditions for nonmonotonic vortex interaction in two-band superconductors Type A1 Journal article
  Year 2011 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B  
  Volume 83 Issue 21 Pages 214523-214523,6  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract We describe a semianalytic approach to the two-band Ginzburg-Landau theory, which predicts the behavior of vortices in two-band superconductors. We show that the character of the short-range vortex-vortex interaction is determined by the sign of the normal domain-superconductor interface energy, in analogy with the conventional differentiation between type I and type II superconductors. However, we also show that the long-range interaction is determined by a modified Ginzburg-Landau parameter κ*, different from the standard κ of a bulk superconductor. This opens the possibility for nonmonotonic vortex-vortex interaction, which is temperature dependent, and can be further tuned by alterations of the material on the microscopic scale.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos (down) 000292252300009 Publication Date 2011-06-30  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.836 Times cited 46 Open Access  
  Notes ; Discussions with A. Moreira, A. Shanenko, R. Prozorov, and A. Golubov are gratefully acknowledged. This work was supported by the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP), the bilateral project FWO-CNPq, CAPES, and PRONEX/CNPq/FUNCAP. ; Approved Most recent IF: 3.836; 2011 IF: 3.691  
  Call Number UA @ lucian @ c:irua:90922 Serial 477  
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Author Vodolazov, D.Y.; Peeters, F.M. url  doi
openurl 
  Title Heating of quasiparticles driven by oscillations of the order parameter in short superconducting microbridges Type A1 Journal article
  Year 2011 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B  
  Volume 83 Issue 22 Pages 224523-224523,6  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract We predict heating of quasiparticles driven by order parameter oscillations in the resistive state of short superconducting microbridges. The finite relaxation time of the magnitude of the order parameter |Δ| and the dependence of the spectral functions both on |Δ| and the supervelocity Q are the origin of this effect. Our results are opposite to those of Aslamazov and Larkin [ Zh. Eks. Teor. Fiz. 70 1340 (1976)] and Schmid et al. [ Phys. Rev. B 21 5076 (1980)] where cooling of quasiparticles was found.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos (down) 000292218200010 Publication Date 2011-06-29  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.836 Times cited 4 Open Access  
  Notes ; This work was supported by the Russian Foundation for Basic Research, Russian Agency of Education under the Federal Target Programme “Scientific and educational personnel of innovative Russia in 2009-2013,” Flemish Science Foundation (FWO-Vl), and the Belgian Science Policy (IAP). ; Approved Most recent IF: 3.836; 2011 IF: 3.691  
  Call Number UA @ lucian @ c:irua:90924 Serial 1415  
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Author Philippaerts, A.; Goossens, S.; Vermandel, W.; Tromp, M.; Turner, S.; Geboers, J.; Van Tendeloo, G.; Jacobs, P.A.; Sels, B.F. pdf  doi
openurl 
  Title Design of Ru-zeolites for hydrogen-free production of conjugated linoleic acid Type A1 Journal article
  Year 2011 Publication Chemsuschem Abbreviated Journal Chemsuschem  
  Volume 4 Issue 6 Pages 757-767  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract While conjugated vegetable oils are currently used as additives in the drying agents of oils and paints, they are also attractive molecules for making bio-plastics. Moreover, conjugated oils will soon be accepted as nutritional additives for functional food products. While current manufacture of conjugated vegetable oils or conjugated linoleic acids (CLAs) uses a homogeneous base as isomerisation catalyst, a heterogeneous alternative is not available today. This contribution presents the direct production of CLAs over Ru supported on different zeolites, varying in topology (ZSM-5, BETA, Y), Si/Al ratio and countercation (H+, Na+, Cs+). Ru/Cs-USY, with a Si/Al ratio of 40, was identified as the most active and selective catalyst for isomerisation of methyl linoleate (cis-9,cis-12 (C18:2)) to CLA at 165 °C. Interestingly, no hydrogen pre-treatment of the catalyst or addition of hydrogen donors is required to achieve industrially relevant isomerisation productivities, namely, 0.7 g of CLA per litre of solvent per minute. Moreover, the biologically most active CLA isomers, namely, cis-9,trans-11, trans-10,cis-12 and trans-9,trans-11, were the main products, especially at low catalyst concentrations. Ex situ physicochemical characterisation with CO chemisorption, extended X-ray absorption fine structure measurements, transmission electron microscopy analysis, and temperature-programmed oxidation reveals the presence of highly dispersed RuO2 species in Ru/Cs-USY(40).  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Weinheim Editor  
  Language Wos (down) 000292214000009 Publication Date 2011-04-20  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1864-5631; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 7.226 Times cited 24 Open Access  
  Notes Fwo Approved Most recent IF: 7.226; 2011 IF: 6.827  
  Call Number UA @ lucian @ c:irua:90352 Serial 660  
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Author Dixit, H.; Tandon, N.; Cottenier, S.; Saniz, R.; Lamoen, D.; Partoens, B.; van Speybroeck, V.; Waroquier, M. pdf  url
doi  openurl
  Title Electronic structure and band gap of zinc spinel oxides beyond LDA : ZnAl2O4, ZnGa2O4 and ZnIn2O4 Type A1 Journal article
  Year 2011 Publication New journal of physics Abbreviated Journal New J Phys  
  Volume 13 Issue 6 Pages 063002-063002,11  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)  
  Abstract We examine the electronic structure of the family of ternary zinc spinel oxides ZnX2O4 (X=Al, Ga and In). The band gap of ZnAl2O4 calculated using density functional theory (DFT) is 4.25 eV and is overestimated compared with the experimental value of 3.83.9 eV. The DFT band gap of ZnGa2O4 is 2.82 eV and is underestimated compared with the experimental value of 4.45.0 eV. Since DFT typically underestimates the band gap in the oxide system, the experimental measurements for ZnAl2O4 probably require a correction. We use two first-principles techniques capable of describing accurately the excited states of semiconductors, namely the GW approximation and the modified BeckeJohnson (MBJ) potential approximation, to calculate the band gap of ZnX2O4. The GW and MBJ band gaps are in good agreement with each other. In the case of ZnAl2O4, the predicted band gap values are >6 eV, i.e. ~2 eV larger than the only reported experimental value. We expect future experimental work to confirm our results. Our calculations of the electron effective masses and the second band gap indicate that these compounds are very good candidates to act as transparent conducting host materials.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Bristol Editor  
  Language Wos (down) 000292137500002 Publication Date 2011-06-03  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1367-2630; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.786 Times cited 98 Open Access  
  Notes Iwt; Fwo; Bof-Noi Approved Most recent IF: 3.786; 2011 IF: 4.177  
  Call Number UA @ lucian @ c:irua:89555 Serial 1008  
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